Don't even try. Instead, give it toys it can chew on. Simply say "good dog" when it plays with its own toys. Don't buy puppy toys that are small enough to be ingested. Don't skimp on the toys. Occasionally, vary your dog's selection to keep it interesting. Spending a little more on dog toys is a lot less expensive than buying new shoes or replacing the legs on your dining room table.
Puppies that never get in the habit of chewing on electrical cords, shoes or table legs aren't likely to find themselves inclined to do so later in life.
When you're busy, either confine the pup to the kitchen or take it around the house on a leash. Keep a favorite toy in your pocket. If the puppy begins swatting at an electrical cord, get the pup's attention and firmly say, "No." Then tell the pup, "Sit." When it does so, reward it with the toy from your pocket.
Don't leave a puppy free to roam the house alone until it is 9 or 10 months old, at the earliest. Leaving a young pup with the run of the house may be downright dangerous. Even a pup that has been well-behaved might get bored or curious enough to chew on an electrical cord. If you leave the house, either crate the dog with chew toys or keep it confined in a puppy playpen or a room such as the kitchen.
Once the pup has found a favorite household object (like a table leg) to chew, it will want to return. Allow it to return, and hide behind a wall to observe. Toss an empty soda can filled with three or four pennies when the dog starts to chew. The idea isn't to injure your pup with a major-league soda-can toss. Rather, the hope is that your pup will think, "When I chew this, a horrible noise comes from the sky and lands right near me. I won't do this again!"